 /*******************************************************************************
  * Copyright (c) 2006, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  * Brad Reynolds - bug 164653
  *******************************************************************************/

 package org.eclipse.core.databinding.observable.map;

 import java.util.Collections ;
 import java.util.HashMap ;
 import java.util.HashSet ;
 import java.util.Iterator ;
 import java.util.Map ;
 import java.util.Set ;

 import org.eclipse.core.databinding.observable.Diffs;
 import org.eclipse.core.databinding.observable.Realm;

 /**
  *
  * <p>
  * This class is thread safe. All state accessing methods must be invoked from
  * the {@link Realm#isCurrent() current realm}. Methods for adding and removing
  * listeners may be invoked from any thread.
  * </p>
  * @since 1.0
  */
 public class WritableMap extends ObservableMap {

     /**
      *
      */
     public WritableMap() {
         this(Realm.getDefault());
     }
     
     /**
      * @param realm
      */
     public WritableMap(Realm realm) {
         super(realm, new HashMap ());
     }

     /**
      * Associates the provided <code>value</code> with the <code>key</code>. Must be invoked from the current realm.
      */
     public Object put(Object key, Object value) {
         checkRealm();
         Object result = wrappedMap.put(key, value);
         if (result==null) {
             fireMapChange(Diffs.createMapDiffSingleAdd(key, value));
         } else {
             fireMapChange(Diffs.createMapDiffSingleChange(key, result, value));
         }
         return result;
     }

     /**
      * Removes the value with the provide <code>key</code>. Must be invoked from the current realm.
      */
     public Object remove(Object key) {
         checkRealm();
         Object result = wrappedMap.remove(key);
         if (result!=null) {
             fireMapChange(Diffs.createMapDiffSingleRemove(key, result));
         }
         return result;
     }

     /**
      * Clears the map. Must be invoked from the current realm.
      */
     public void clear() {
         checkRealm();
         Map copy = new HashMap (wrappedMap.size());
         copy.putAll(wrappedMap);
         wrappedMap.clear();
         fireMapChange(Diffs.createMapDiffRemoveAll(copy));
     }

     /**
      * Adds the provided <code>map</code>'s contents to this map. Must be invoked from the current realm.
      */
     public void putAll(Map map) {
         checkRealm();
         Set addedKeys = new HashSet (map.size());
         Map changes = new HashMap (map.size());
         for (Iterator it = map.entrySet().iterator(); it.hasNext();) {
             Map.Entry entry = (Entry) it.next();
             Object previousValue = wrappedMap.put(entry.getKey(), entry.getValue());
             if (previousValue==null) {
                 addedKeys.add(entry.getKey());
             } else {
                 changes.put(entry.getKey(), previousValue);
             }
         }
         fireMapChange(Diffs.createMapDiff(addedKeys, Collections.EMPTY_SET, changes.keySet(), changes, wrappedMap));
     }

 }

